Third party networking software such as Hamachi can cause issues. Try uninstalling / disabling this software.

Make sure outgoing UDP ports 5055 - 5100 are not blocked and are being properly routed.

Make sure your router's firmware is up to date

Sometimes restarting your router / networking gear can help

If you are using Steam: Try verifying the game cache

If you downloaded the game directly: Redownload the game

If you are still having issues you can contact us at team@leafygames. If you can send us your output_log file and let us know the region you are connecting from it would help us fix the issue. You can send us an output log file by using the instructions at this link: http://pulsarthegame.com/sending-an-output-log-file